The Figure Given Below Shows the Revenue and Cost Curves

The figure given below shows the revenue and cost curves of a perfectly competitive firm. Figure 23.2 MC: Marginal cost curve
MR: Marginal revenue curve
ATC: Average-total-cost curve
AVC: Average-variable-cost curve
Refer to Figure 23.2.If the market price falls to $10, the firm would produce:

A) nothing.
B) 15 units.
C) 5 units.
D) 10 units.
E) 20 units.